Knowledge Bank

Vibration rotation spectra of the protonated rare gases have been found for $HeH+1,NeH+2$ and $ArH+3$. Whereas the absorption $experiments1,2$ give information only on the fundamental bands, emission $spectroscopy3$ can give much more information on the potential curves of these molecular ions. Emission from various hollow cathode sources have been examined using a Bomem Fourier transform spectrometer. The spectrum of $KrH+(\upsilon 1-0=2413.6cm-1)$ has been observed and further experiments with Xenon are planned. Attempts to record emission from $HeH+$ and $NeH+$ were not successful but the earlier observation of $ArH+$ has been repeated and in addition the spectrum of $ArD+$ has been observed.